TCS Daily


On Global Warming, We Know What We Don't Know

By Duane D. Freese - December 5, 2001 12:00 AM

After nearly a decade of heated debate about climate change, the effect of human activities on global warming is still one great big unknown. The lack of light on that issue results from one thing - too much politics and not enough solid science.

That's the bottom line in a report, Climate Science and Policy, Making the Connection, issued this week by the George C. Marshall Institute, a nonprofit research institute that provides scientific and technical advice on matters that shape public policy. The report was written by Dr. Lenny Bernstein, a lead author for the United Nation's Intergovernmental Panel on Climate Change Third Assessment Report released earlier this year, with the help of a working group of distinguished scientists, economists and public policy experts.

It comes just as the Bush administration prepares final climate change policy recommendations in the aftermath of U.N. meetings in Brussels, Bonn and Marrakech adopting plans for reducing human emissions of greenhouse gases that are blamed for warming the planet.

The Marshall work group, though, concluded that "the IPCC's findings about human influence on the climate are not supported by the underlying science," Institute President William O'Keefe told reporters and policy analysts at a briefing Tuesday at the National Press Club.

O'Keefe said the IPCC summaries, in particular, were essentially politically brokered so they failed to show the tremendous uncertainties behind projections of future climate change. The models on which the projections were based suffer from a lack of good data from previous years coming in and poor simulation of actual climatic conditions, he said.

The Marshall report itself, which O'Keefe summarized, said specifically: "The IPCC findings have been presented with a degree of certitude that is not justified by the underlying science. The IPCC concludes that human activities were responsible for most of the observed global average surface temperature since 1861 with model simulations of surface temperatures. However, these model simulations fail to reproduce the difference in temperature trends in the lower to mid-troposphere and at the surface over the past 20 years. The National Academy of Science finds this difference to be real but inconsistent with the prevailing global warming theory."

The reasons for the data problems are threefold: uneven geographic coverage, lack of historical data for sea surface temperatures, and inattention to the urban heat island effect, which now some experts believe could result in a fifth of the recorded 0.5 degree Celsius surface temperature rise reported over the last century.

In addition, the model simulations' projecting temperature changes of 1.4 degrees C to 5.8 degrees C in the next century are uncertain for three key reasons as well: poor characterization of clouds, water vapor aerosols, ocean currents, radiation transfer in the atmosphere; assumptions that the models account for natural, non-human variability, when they don't, and omission of known influences on climate, such as black soot.

These deficiencies leave policymakers with statements of certainty about climate change that can lead to policies that solve nothing while causing tremendous economic harm. "Actions have consequences," O'Keefe said. "And it's tremendously expensive to reduce greenhouse gases. Someone will have to pay for that."

The Marshall Institute report, though, isn't a call on government to do nothing, O'Keefe said. "A lot of things can be done," he noted. Businesses can involve themselves in voluntary programs that increase energy efficiency, such as the Energy Star project. "As capital stock turns over, businesses can employ more efficient machines and use less energy, and that, by definition, is cost effective."

But the most important government needs to do now is to get better information on climate change. "Better data is the road to get better policy," O'Keefe said.

The report says that the U.S. Global Change Research Program is, in reality, "not a program, as it lacks a comprehensive strategy, a mechanism for prioritization of research and adequate funding.

The country needs a cost effective program on climate change, and that requires focused research programs that address relevant scientific uncertainties, a long-term commitment to climate observation and data collection, improved scientific assessments and a process for integrating information to make it useful to policymakers.

At the same time, the IPCC could reduce the politicization resulting from the writing of its summaries by including "a listing of robust findings and key uncertainties in every summary."

The failure of the country and the United Nations over the last 10 years to do exactly that leads to the situation today where policymakers are faced with making costly decisions with a lack of real evidence that what they do will accomplish much, if anything at all.
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